WebAssembly

The official WebAssembly logo

WebAssembly (abbreviated Wasm) is a binary instruction format for a stack-based virtual machine. It is designed as a portable compilation target for programming languages, enabling deployment on the web for client and server applications.

Overview

WebAssembly is a low-level bytecode format that can be executed in web browsers. It is designed to be a compilation target for high-level languages like C, C++, and Rust, allowing these languages to run on the web with near-native performance.

WebAssembly is supported by all major web browsers, including Google Chrome, Mozilla Firefox, Microsoft Edge, and Apple Safari. It is developed by the W3C and is considered a web standard.

Features

WebAssembly provides several key features:

• Portability: WebAssembly code can run on any platform that has a WebAssembly runtime, making it highly portable.
• Performance: WebAssembly is designed to execute at near-native speed by taking advantage of common hardware capabilities.
• Security: WebAssembly runs in a sandboxed execution environment, which helps to protect the host system from potentially malicious code.
• Interoperability: WebAssembly can interoperate with JavaScript, allowing developers to call WebAssembly functions from JavaScript and vice versa.

Architecture

WebAssembly is based on a stack machine architecture. It uses a binary format that is compact and efficient to parse, making it suitable for fast download and execution in web browsers.

The WebAssembly module is the basic unit of code in WebAssembly. A module contains functions, tables, memories, and global variables. Functions are the primary building blocks of WebAssembly code, and they are defined using a simple instruction set.

Development

WebAssembly was first announced in 2015 and has since become a key technology for web development. It is developed by a consortium of major technology companies, including Google, Mozilla, Microsoft, and Apple.

The WebAssembly specification is maintained by the W3C WebAssembly Working Group. The group is responsible for defining the core features of WebAssembly and ensuring its compatibility across different platforms.

Applications

WebAssembly is used in a variety of applications, including:

• Web applications: WebAssembly allows developers to run complex applications in the browser, such as games, video editors, and CAD software.
• Server-side applications: WebAssembly can be used on the server side, enabling developers to run WebAssembly code in environments like Node.js.
• Embedded systems: WebAssembly's portability makes it suitable for use in embedded systems and IoT devices.

Future Developments

The WebAssembly community is actively working on several future developments, including:

• Garbage collection: Adding support for garbage collection to improve the performance of languages that rely on it.
• Threads: Enhancing support for multithreading to allow WebAssembly applications to take advantage of multi-core processors.
• SIMD: Adding support for Single Instruction, Multiple Data (SIMD) to improve performance for certain types of computations.

Related pages

• JavaScript
• HTML5
• World Wide Web Consortium
• Node.js